Textile treating process



United States Patent 3,230,032 TEXTILE TREATING PROCESS Lucien Lepere, Calais, France, assignor to Zschirnmer & Schwarz, Alte, Germany No Drawing. Fided Apr. 25, 1962, Ser. No. 189,988 Claims priority, appiication Germany, Apr. 28, 1961, Z 8,709, Z 8,710 16 Qiaims. (Cl. 8-137) My invention generally relates to textile finishing processes and is particularly concerned with a method of removing impurities from net-like textile products made from synthetic fibers.

In the manufacture of net-like textile products such as lace, open work, curtain fabrics, tulle and the like from synthetic fibers such as, for example, nylon, Perlon, Rilsan, Dralon, Terylene, etc., a finished netting is usually obtained which has a soiled grayish appearance caused by the presence of graphite particles or graphite-containing substances which lodge themselves on the fiber surfaces and within the fiber structures and pores. The graphite emanates from the materials which are used in the finishing and sizing of such net-like textile products and also from the lubricants of the textile machinery, e.g., the looms on which the netting has been produced. The graphite deposits on the net-like products impart to the products a grayish color which obviously is undesired. Serious attempts have been made to remove the graphite deposits from the textile fiber surfaces by washing the nettings with the usual washing agents. These attempts, however, have only been partially successful. A major portion of the graphite deposits can usually be removed by ordinary washing procedures, particularly if a synthetic washing agent with surface active characteristic is employed. However, as is well known in the industry, it has been extremely difficult, if not impossible, completely to remove such graphite deposits from fiber structures of synthetic origin as small residues or traces of graphite tend to remain on the fiber surfaces. Thus, for example, experience has conclusively established that even prolonged washing of, for example, nylon lace for 24 hours with synthetic, sunface active washing agents does not completely wash out the graphite but traces remain. These traces seriously detract from the appearance of the product and particularly its color. In addition, the remaining traces of graphite deposits usually are not uniform but are distributed in spot-like manner so that some areas of the netting, such as lace or tulle, appear grayer than other areas.

It has also been suggested frequently to change the washing liquid in order thereby more successfully to remove the graphite deposits. However, even such procedures have not met with success. In this connection, it should also be recognized that repeated and prolonged washing of relatively delicate textile structures such as lace and tulle seriously affects the products as mechanical washing action tends to distort the respective pattern of the lace or tulle by dislocating the threads and/ or individual threads may tear. Generally, of course, prolonged washing is bound to be detrimental to the appearance and mechanical strength of the product.

Although many theories have been advanced for explaining the difiiculties in removing graphite particles from synthetic fiber structures, different opinions prevail among the experts in this respect. Generally speaking, it is believed that exceedingly strong adhesion and cohesion forces exist between the synthetic fibers and the fine graphite particles which forces apparently cause a strong bond between the graphite [particles and the synthetic fiber surfaces.

Accordingly, it is a primary object of my invention to provide a procedure for efiectively and totally removing 3,23%,d32 Patented Jan. 18, 1966 graphite particles and the like impurities from synthetic fiber material in a rapid and simple manner.

Another object of my invention is to provide a process for effectively cleaning graphite contaminated net-like textile products of synthetic fibers in a simple and inexpensive manner without affecting the strength or pattern formation of the netting.

Generally speaking, it is an object of my invention to improve on the art of cleaning and washing textile materials as presently practiced.

Briefly, and in accordance with my invention, I have ascertained that wool fat and oxethylated wool fat, if employed under the conditions hereinafter described, effectively remove graphite from synthetic fibers. Thus, if the wool fat or oxethylated wool cfat is applied to a synthetic fiber surface the forces between the graphite particles and the synthetic fiber material are overcome and the graphite is effectively removed from the fiber surface upon removal of the wool fat or oxethylated wool fat, respectively.

According to one embodiment of my inventive procedure, wool fat per se, in chemically unmodified form, is first emulsified in an aqueous system and the aqueous emulsion, preferably in diluted form, is then applied to the textile fiber structure. The emulsion may advantageously be prepared by stirring molten wool fat, that is crude lanolin, with a relatively large amount of warm water of a temperature of about, for example, 40 to C. in the presence of a suitable emulsifier. I have found that non-ionic emulsifiers are particularly suitable for the inventive purpose. The application of the emulsion may be effected in any suitable manner, for example, by dipping the textile product into the aqueous emulsion or by otherwise impregnating the product therewith. The emulsion breaks upon contact with the fibers and in this manner, a thin layer of wool fat adheres on the individual synthetic fibers. The wool fat is then removed from the textile fibers as by applying soap, as for example curd soap, whereby re-emnlsification of the wool fat takes place. The textile product is then rinsed. Textile products treated in this manner are completely free from any traces of graphite.

If desired, the textile product may additionally be subjected to an after-treatment with a non-ionic substance. The procedure may be repeated or, after the removal of the wool fat by the application of the soap and rinsing, the textile product may be washed with potash or soft soap.

According to this embodiment of my invention, the procedure thus essentially resides in first applying a thin layer of wool fat on the textile fibers and thereafter removing the wool fat by dispersion and washing procedures. In proceeding in this manner, the wool fat acts as carrier for the impurities, that is, the graphite or graphite-containing substances.

As the process according to this embodiment basically aims at bringing the adhering graphite impurities into a condition in which they can be removed from the synthetic fiber surfaces and can be dispersed, it is advantageous to employ a wool fat emulsion which is not too finely dispersed, i.e., to a certain degree unstable. In fact, I have found that superior results are obtained if the stability of the wool fat emulsion or dispersion is adjusted so that, considering the conditions under which the emulsion is applied to the netting, the emulsion completely or partially breaks upon application so that wool fat proper settles on the fiber surfaces. It is, of course, well known in the art to control and adjust the stability of emulsions by using suitable emulsifiers in controlled amounts.

In essence, therefore, this first embodiment of my invention comprises two stages, that is, an application stage wherein the wool fat in dispersed form is applied to the fibers so that the dispersion breaks and wool fat proper lodges itself on the fibers, and a second stage wherein the wool fat is again emulsified or dispersed by the application of soap such as curd soap and subsequently removed by rinsing or washing with water.

Contrary to the known washing procedures with ordinary washing agents, the application of the wool fat rapidly, effectively and completely removes the graphite from the fibers. The resulting product, therefore, is completely white and no traces of graphite can be detected.

According to a second embodiment of my invention, I eliminate the re-emulsification of the wool fat with soap by employing, instead of wool fat proper, oxethylated wool fat. The term oxethylated wool fat is deemed to refer to wool fat derivatives which are obtained by reacting wool fat with ethylene oxide. From a practical point of view, oxethylated wool fat as used by me is the addition pro-duct of about 100 parts by weight of wool fat with 50 to 150 parts by weight of ethylene oxide. Particularly favorable results are obtained if the oxethylated product contains 75 to 100 parts by weight of ethylene oxide per 100 parts by weight of wool fat.

The addition reaction of ethylene oxide to wool fat is a generally known procedure not forming the subject of my invention. Thus, for example, a process of oxethylating wool fat by reacting wool fat with ethylene oxide is described in the book by Nikolaus Schiinfelt, Ober fiachenaktive Anlagerungsprodukte des lithylenoxyds, ihre Herstellung, Eigenschaften und Anwendung (Wissenschaftliche Verlagsgessellschaft m.b.H., 1959). The reaction between the ethylene oxide andthe wool fat is preferably carried out in accordance with such prior art process in the presence of caustic alkali as catalyst and at a temperature of about 150 C.

As previously mentioned, the use of oxethylated wool fat has the advantage that re-emulsification by means of soap after application to the fiber surface is rendered unnecessary, so that this embodiment of my invention resides in a one-step procedure which, of course, reduces the treatment time and the expenditure, such as plant equipment and raw material.

I have ascertained that particularly favorable results are obtained if the oxethylated wool fat is applied in solution, for example, in water, and the solution contains low molecular aliphatic alcohols of 1 to 4 carbon atoms. The presence of these alcohols tends to facilitate penetration of the textile material by the oxethylated wool fat, thereby enhancing the graphite removal. The following lower aliphatic alcohols are particularly suitable as addition to the oxethylated wool fat containing system: methyl-, ethyl-, propyl-, isopropyland butyl-alcohol. However, in addition to these alcohols, other substances can be used which facilitate wetting and emulsification, as for example, triethanol amine. In the event that the treatment bath contains alcohols of the nature indicated, the amount of water can be reduced.

However, the success of the operation is not dependent on the pressure of the alcohols referred to and excellent results are obtained if the oxethylated wool fat is simply dissolved in water and the aqueous solution is then applied to the textile products.

My experience has also shown that the results may be improved if the bath or liquid contains small amounts of electrolytes. Thus, sodium sulfate in the form of a cold saturated aqueous solution may be added to the bath. Instead of sodium sulfate, other electrolytes can be used, provided they do not adversely affect the graphite removing activity of the oxethylated wool fat and do not attack the textile material, such as by discoloration. For example, the sodium sulfate may be replaced by a sodium chloride solution. In all instances, I have found that concentrated electrolyte solutions give the best results.

I have, for example, carried out experiments with the following electrolytes which were then added in small quantities to the oxethylated wool fat containing liquid: grams of anhydrous sodium sulfate dissolved in 1 liter of water. 5 grams of hexasodium tetrapolyphosphate were added for the complex formation of hardness causing salts (15 B.).

280 grams of sodium chloride in crystallized form dissolved in 1 liter of water with the addition of 5 grams of hexasodium tetrapolyphosphate (23 B.).

The electrolytes may also contain oxalic acid, and generally sodium hydroxide, sodium triphosphate or sodium pyrophosphate may be employed.

According to this second embodiment of my invention, treatment liquids of high concentration are used so that the amount of water in the liquid is relatively low. The textile product to be treated is submerged in or impregnated with the treatment liquid.

Very advantageous results are obtained if the textile products are subjected to the action of the concentrated treatment liquid, while being passed through squeezing roller-containing machinery wherein the roller pressure is adjustable. The treatment of the textile products in the squeezing roller-containing machinery should preferably be effected at relatively low temperatures. At the end of the treatment, the textile products are rinsed with water, whereby clean. white nettings such as lace, tulle, curtain fabric, etc. are obtained without any traces of graphite.

The invention will now be described with reference to several examples, it being understood, however, that these examples are given by way of illustration and not by way of limitation and that many changes may be effected in process conditions, amount of quantities, etc. without affecting in any way the scope and spirit of this invention as recited in the appended claims.

Example I A wool fat emulsion was prepared in the following manner: 52.5 parts by weight of molten wool fat (lanolin), 2.5 parts by weight of olein, 5 parts by weight of a. non-ionic emulsifier such as lauryl alcohol with 26A0 and 40 parts by weight of warm water were intimately mixed, preferably with the aid of a homogenizer, whereby a somewhat unstable wool fat emulsion was obtained.

The textile product to be treated consisted of 10 kg. of a net-like curtain fabric of synthetic fiber material of polyester 1 which had a strongly gray appearance caused by the presence of graphite and other contaminants on and within the fiber structure. The process was carried out in a washing machine of customary construction as used in the textile industry. The washing machine was fitted with opposing pressure rollers through which the curtain fabric was passed during the washing procedure. The pressure of the rollers was adjustable. The fabric was impregnated with the wool fat emulsion of the nature described. This was effected by mixing 300 to 500 grams of the emulsion with an equal amount of water and adding the diluted emulsion thus obtained to 200 liters of cold water contained in the washing machine. 300 to 500 grams of the emulsion corresponds to 3 to 5% of the weight of the textile goods. The machine was started and after about 20 minutes, the curtain fabric had a pro nounced fatty feel. The major portion of the graphite particles had been removed from the textile product and was contaminating the bath liquid. The thus soiled bath liquid was thereafter discharged and replaced by clean, soft water. The fabric was rinsed in clean water until the water remained clear. Thereafter, in the presence of a small amount of water (about 10 to 15 liters) and while the machine was running, 600 grams of curd soap in flake form were added to the water. A dense foam of small bubbles was formed. After the formation of the foam, the machine was operated for an additional 15 to 30 minutes, dependent on the degree of soiling. There- Diolen (trade name of Vereinigte Glanzstotf-Fabriken).

after, 100 grams of a liquid non-ionic surface active substance, for example a solution of alkylphenolethylenoxy addition product was added to the bath and the machine was operated for an additional 30 minutes. The bath liquid was thereafter discharged and the textile product was rinsed with running cold or slightly heated water.

In the event that the textile product, after this treat ment, should still have a fatty feel, an additional washing with potash soap or soft soap may be carried out. This last-mentioned treatment effectively removes any traces of wool fat which may still adhere to the fibers. This again, at the same time, effectively and totally removes any remaining traces of graphite. The curtain fabric obtained thereafter, after drying, was completely clean and had not the slightest gray tint.

Example II 10 kg. of a solution having the following composition were prepared: 20 parts by weight of oxethylated wool fat (lanolin technical grade), parts by weight of water, 64 parts by weight of ethyl alcohol, 1 part by weight of a cold saturated aqueous sodium sulfate solution.

10 kg. of strongly graphite-soiled nylon lace was thereafter impregnated with the solution on a Foulard. Thereafter, the lace, in the form of an endless hose, was treated for 5 0 minutes in a textile washing machine. The washing machine had the usual treatment rollers of adjustable pressure. No water was added to the washing machine. The lace was then thoroughly rinsed with cold water. Clean lace without any traces of graphite was obtained. The treatment was effected at a temperature of about C. or slightly lower.

In the event that the lace contains particularly stubborn graphite deposits, an intermediate step wherein curd soap is applied to the lace may be interpositioned. This is advantageously effected by sprinkling easily soluble curd soap flakes or powder into the machine without the addition of water. When the machine is started up, a dense foam is formed. After 10 to 15 minutes of this treatment, the lace is then rinsed and any traces of oxethylated wool fat and/or graphite are thus completely removed.

The amount of wool fat oxethylate-alcohol mixture and the time period during which the lace is subjected to the action of the treatment liquid are dependent on the degree of soiling of the lace. The soiling generally varies considerably, dependent on the manner in which the lace is produced.

Lace which is soiled to a small degree only can be impregnated with water prior to the treatment with the wool fat derivative proper. The water is squeezed out or centrifuged to a squeezing effect of about 43 The term squeezing effect in this connection refers to the percentage of liquid absorbed by the previously dry fabric. Thus, a squeezing effect of 43% means that, for example, 100 grams of dry lace absorbs 43 grams of liquid and thus has a weight of 143 grams. If such pre-treatment with water is effected, the required amount of wool fat oxethylatealcohol mixture is then reduced to only 57% calculated on the dry weight of the lace.

Example III This test was carried out with 10 kg. of synthetic fiber lace. The synthetic fiber was a polyamide product such as nylon or Rilsan. The lace was only slightly discolored by graphite contamination, the major amount of the graphite contamination having previously been removed by customary washing procedures. The lace was treated with a wool fat emulsion of the same nature and in the same amounts as described in connection with Example I. The subsequent rinsing was also effected as described in the aforementioned example. After the rinsing and in the presence of a small amount of water (about 10 to 15 liters) and during running of the washing machine, 600 grams of curd soap in flake form was added to the bath.

6 Upon formation of a dense foam of small bubbles, the machine was allowed to run for an additional 45 minutes. A small amount of potash soap (soft soap) was added during this period. The lace was then rinsed with cold or slightly heated water. Clean, white lace was obtained.

Example IV This experiment was carried out with 10 kg. of nylon lace. The lace was soiled by graphite. The soiled lace was impregnated on a Foulard in two runs with 10 kg. of a solution having the following composition: 20 parts by weight of oxethylated wool fat, 60 parts by weight of ethyl alcohol and 20 parts by weight of concentrated aqueous sodium sulfate solution. After impregnation, the lace in the form of an endless hose was treated in a textile washing machine of customary construction having pressure rollers of adjustable pressure The treatment was effected without additional water. After a thorough rinsing with cold water, clean, graphite-free lace was obtained. Any after-treatment with soap was unnecessary.

Example V 10 kg. of Diolen tulle was treated during two runs with a mixture of 12.5 parts by weight of oxethylated wool fat in 37.5 parts of ethyl alcohol and 50 parts of concentrated sodium sulfate solution. After water-rinsing, the tulle was completely free from any graphite contamination.

The wool fat oxethylate-alcohol mixture may be admixed with electrolyte solutions in varying proportions and ratios. For example, the ratio of wool fat oxethylatealcohol mixture to electrolyte may be:

812, corresponding to 20% content of oxethylated wool fif orresponding to 17.5% content of oxethylated wool 6: ii corresponding to 15% content of oxethylated wool fi i orresponding to 12.5% content of oxethylated wool mg iizorresponding to 10% content of oxethylated wool Example VI 25 parts by weight of oxethylated wool fat were dissolved in 75 parts of water. 5 grams per liter of hexasodiumtetrapolyphosphate were added for the complex formation of hardness causing salts.

100 kg. of tulle of polyester fibers such as Terylene or Diolen were thereafter treated in a textile washing machine with adjustable treatment rollers. The tulle was considerably contaminated by graphite.

The treatment in the washing machine was carried out in two stages as follows:

First bath.2 to 4 liters of sodium hydroxide (30 B.), 2 to 4 liters of the aqueous solution of oxethylated wool fat of the composition given hereinabove. The machine was run for 10 minutes without heating. Thereafter, the solution was gradually heated to to C. while the machine was running. After 30 minutes of treatment at this temperature, the bath solution was discharged and the product was rinsed with cold water.

A second bath was prepared containing 200 liters of water of a temperature of about 40 to 50 C., 1 kg. of oxalic acid and 0.4 kg. of the aqueous solution of the oxethylated wool fat of the composition previously described in this example. This bath liquid was rapidly heated to 80 C. while the machine was running and was maintained at this temperature for about 30 minutes. Thereafter, the tulle was rinsed with cold water. Exoellent results were obtained within a short period of time. The graphite contaminations were completely removed and the tulle was clean and completely white.

'7 Example VII This test was performed with synthetic fiber marquisettes of Diolen which were only slightly soiled by fat, rust, lubricating oil, etc. As is well known, marquisettes are very delicate structures which cannot be subjected to rough mechanical treatments, as otherwise the thread patterns are dislodged and tear. Therefore, any strong mechanical movements such as agitation has to be avoided. The cleaning treatment was therefore carried out on a textile washing machine of the jigger type having a width capable of accommodating the width of the marquisettes. The machine was provided with pressure rollers.

The washing machine contained the following bath liquid: 250 liters of cold water, 1.25 kg. of oxalic acid and 10 to 12 liters of the aqueous oxethylated wool fat containing solution of Example VI. The material was passed through the unheated bath several times, whereafter the material was run through the machine for an additional number of times while the bath was heated to about 40 C. Finally, the marquisettes were run through the bath an additional number of times with a bath temperature of 80 C. A total of 10 to 15 runs is usually sufiicient. The marquisettes were thereafter rinsed with running Water. A clean product was obtained.

Example VIII This test was carried out with 100 kg. of strongly soiled and yellowed tulle made from polyester fibers such as Tergal or Terylene. The tulle was sensitive to strong mechanical action, as such action results in displacement of the individual threads forming the tulle pattern. The washing was therefore effected in a jigger without tension.

The treatment was carried out in two stages:

(1) The tulle was treated in the jigger containing the following solution: 200 liters of concentrated sodium sulfate solution which was enriched with 5 grams per liter of hexasodium tetrapolyphosphate and 5 liters of sodium hydroxide solution (30 B.). The success of the treatment was not affected by increasing the amount of the sodium hydroxide solution to liters. The tulle was passed through the cold solution. Thereafter, the solution was heated gradually to 40 C. and finally to 80 C. The tulle was repeatedly passed through the bath solution at the indicated temperature ranges. A total of 10 to runs through the bath was suflicient. Upon rinsing with cold water, excellent results were obtained.

(2) The tulle was then treated in the same jigger with a bath solution of the following composition: 250 liters of water of a temperature of 40 C., 1.25 kg. of oxalic acid and 10 liters of an aqueous solution containing oxethylated lanolin. The solution was rapidly heated to 80 C. and at this temperature the tulle was passed through the jigger 7 to 8 times.

The sodium hydroxide solution in the first bath liquid can be replaced by sodium pyrophosphate or trisodium phosphate in the event that textile fabrics made from a mixture of polyester fibers and wool are to be cleaned.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

The following emulsifiers are suitable for preparing the emulsion with wool fat: fatty alcohols with 2228 ethylene oxide.

The following non-ionic dispersion agents may be used for the aftertreatment of the textile structures: fatty alcohols with 8-12 ethylene oxide, nonyl-phenol with 69 ethylene oxide.

What is claimed is:

1. A method of removing graphite-containing con- 8. taminants from synthetic fibers, which comprises applying a layer of a member selected from the group consisting of wool fat and oxethylated wool fat on said fibers, and then removing the layer of said member from said fibers.

2. A method of removing graphite-containing impuri- .ties from net-like textile structures of synthetic fibers,

which comprises depositing fool fat on said fiber strucvtures and thereafter removing said wool fat from said structures.

3. A method of removing graphite-containing contaminants from net-like textile structures of synthetic fiber material, which comprises depositing a wool fat emulsion layer on the textile structures, thereafter applying soap to said layer and removing the soapy layer from said textile structures by washing with water.

4. A method of removing graphite-containing contaminants from net-like textile structures of synthetic fiber material, which comprises preparing an aqueous unzstable wool fat emulsion, applying said wool fat emulsion to the fiber structures, breaking said emulsion on said fiber structures to obtain a wool fat layer thereon, re-emulsifying the wool fat on said fiber structures, and removing the re-emulsified wool fat from said textile structures by rinsing with water.

5. A method as claimed in claim 4, wherein said reemulsification is performed with soap.

6. A method as in claim 5, wherein after rinsing, the textile structures are contacted. with a non-ionic dispersing substance.

7. A method of removing graphite-containing contaminants from net-like textile structures of synthetic fiber material, which comprises impregnating the textile structures with an oxethylated wool fat containing liquid and rinsing said structures thereafter with water.

8. A method as claimed in claim 7, wherein said liquid contains a lower aliphatic alcohol.

9. A method as claimed in claim 8, wherein said alcohol is selected from the group consisting of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol and butyl alcohol.

10. A method as claimed in claim 7, wherein said liquid contains water.

11. A method as claimed in claim 7, wherein said liquid contains a minor amount of an electrolyte.

12. A method as claimed in claim 11, wherein said electrolyte is selected from the group consisting of sodium sulfate, sodium chloride, caustic soda, sodium triphosphate, sodium pyrophosphate and oxalic acid.

13. A method of removing graphite-containing contaminants from net-like textile structures of synthetic fiber material, which comprises impregnating the textile structures with a liquid containing oxethylated wool fat, an electrolyte, water and a lower aliphatic alcohol of 1 to 4 carbon atoms, and thereafter rinsing the impregnated textile structures with water.

14. A process as claimed in claim 13, wherein after rinsing, said textile structures are contacted with a nonionic dispersion agent.

15. A process as claimed in claim 11, wherein said electrolyte is in the form of a concentrated aqueous solution.

16. A method as claimed in claim 7, wherein said oxethylated wool fat is the addition product of about 50 to to 150 parts by weight of ethylene oxide and about parts by weight of wool fat.

No references cited.

J. TRAVIS BROWN, Acting Primary Examiner.

J. CANNON, Assistant Examiner. 

3. A METHOD OF REMOVING GRAPHITE-CONTAINING CONTAMINANTS FROM NET-LIKE TEXTILE STRUCTURES OF SYNTHETIC FIBER, MATERIAL, WHICH COMPRISES DEPOSITING A WOOL FAT EMULSION LAYER ON THE TEXTILE STRUCTURES, THEREAFTER APPLYING SOAP TO SAID LAYER AND REMOVING THE SOAPY LAYER FROM SAID TEXTILE STRUCTURES BY WASHING WITH WATER. 